I do not believe that is necessarily true. I am stuck in a similar quagmire, with the added complication that I closed out the errant 401K after I left that employer and rolled the entire 401K amount (much more than the excess deferral) into my rollover IRA at Fidelity. What I was told by the former employer is that the definition of a HCE is based upon the employee's income from the prior tax year, in this case 2018.
